Frequently Asked Questions - ADU in San Diego, CA
Straight answers to the questions we hear most from homeowners across San Diego County. If you don't see yours here, call (858) 264-3027 and ask us directly.
Pricing & Cost FAQs
Most ADUs in San Diego run between $180,000 and $350,000 depending on size, site conditions, and finish level. A detached 400-square-foot studio with basic finishes starts near the low end; a two-bedroom unit with a full kitchen and upgraded fixtures lands higher. San Diego's coastal slope lots, older utility lines, and strict coastal-zone rules push costs above the state average. We give a written price before any work starts, so the number you sign is the number you pay. Call (858) 264-3027 for a free estimate on your specific property.
Expect to budget $450 to $700 per square foot for a turnkey ADU in San Diego, with prefab options sometimes landing lower and custom builds higher. Site prep, foundation work, utility connections, and grading on hillside lots in places like La Mesa or Jamul add real cost. Our written quotes break out every line item so you can see exactly where the money goes before work begins. Call (858) 264-3027 and we'll price your project square.
Yes. Our written price includes all San Diego building permits, plan checks, and inspection fees for your ADU. California law requires permits for any attached or detached ADU, and we pull them ourselves, so you never have to deal with the Development Services Department on your own. We schedule the inspections and stay until the final sign-off. Ask for the permit line item in your written estimate by calling (858) 264-3027.
A garage conversion is typically the most affordable ADU path in San Diego because the foundation, walls, and roof already exist. Prefab units like Boxabl or Plant Prefab can also save money when your lot allows a simple set-and-finish install. The cheapest option is not always the best long-term value if your existing garage needs structural upgrades or sewer line replacement. We'll walk you through the real costs of each option in plain numbers. Call (858) 264-3027 for a free written estimate.
No. We put the full price in writing before any work begins, and we do not change it at the door. If you ask for a change mid-project, we price that change in writing before doing the work. Our promise is part of The Garrison Standard: price in writing before any work starts. This is the single biggest reason San Diego homeowners choose us over contractors who quote low and bill high. Call (858) 264-3027 to see a written quote for your project.
Service & Process FAQs
Most ADUs in San Diego take 6 to 10 months from design to final inspection. The city's plan review process usually accounts for 6 to 10 weeks of that timeline. Prefab units from Boxabl or Plant Prefab can trim several months off construction once plans are approved. We schedule every job with a start date and finish date in writing, and we show up inside the window we gave. Call (858) 264-3027 to get a realistic timeline for your property.
First, we walk your property and talk about your goals, then we design the ADU and prepare plans for the city of San Diego permit office. Once permits are approved, our crew builds to the approved plans, with inspections at each required stage. The final step is your certificate of occupancy, and then the ADU is yours. Every phase has a written schedule, and we leave the site clean at the end of every day. Call (858) 264-3027 to start with a free on-site consultation.
Yes. Sloped lots are common in neighborhoods like Encinitas, Alpine, and Jamul, and we engineer foundations that hold on grade. The added cost comes from retaining walls, pier drilling, and drainage work, all of which we include in the written price up front. San Diego's hillside codes require specific engineering and setbacks, and we pull every permit those codes require. Call (858) 264-3027 and tell us your address; we'll tell you what's possible.
Yes. We manage the full process: design, structural engineering, city permits, utility connections, construction, and final inspection. You have one written contract and one point of contact from the first walk-through to the day you get your keys. We don't hand you off to separate designers or third-party project managers. Call (858) 264-3027 and we'll walk you through the entire process before you commit to anything.
We build ADUs across San Diego County, including San Diego, Encinitas, Santee, La Presa, Lakeside, Alpine, Jamul, Del Mar, Coronado, National City, Lemon Grove, and La Mesa. Each city has its own planning department quirks, and we know them all. Call (858) 264-3027 to confirm your address is in our service area and schedule a free estimate.
Brands & Parts FAQs
Yes, we install prefab ADUs from manufacturers including Boxabl and Plant Prefab. Prefab units can save months of construction time and reduce on-site disruption, but they still require a foundations, utility connections, and city permits in San Diego. We handle the site work and installation so the unit lands square and passes inspection the first time. Call (858) 264-3027 to talk through whether a prefab or stick-built ADU fits your lot and budget.
Converting a Tuff Shed into a legal ADU in San Diego is rarely practical. The shed's structure, insulation, and foundation don't meet California residential building code for a dwelling unit, so the city will not issue a certificate of occupancy. A garage conversion, on the other hand, can work well because garages are built to a higher structural standard. We can look at what you have and tell you honestly what will pass inspection. Call (858) 264-3027 for a straight answer.
We use materials rated for San Diego's coastal climate, including James Hardie fiber cement siding, which holds up to salt air and sun better than wood or vinyl. Roofing, windows, and flashing are selected for the marine layer in neighborhoods like Del Mar and Coronado, where moisture exposure is constant. We specify every material in the written quote, by brand and model, so you know exactly what you're paying for. Call (858) 264-3027 to review material options for your ADU.
Licensing & Insurance FAQs
Every contractor working under the Fielding ADU San Diego name is required to hold the license their state requires. The state of California requires a General Building Contractor license for ADU construction, and we meet that requirement. You can verify any contractor's license through the Contractors State License Board before you sign. We encourage it. Call (858) 264-3027 and ask us anything about our credentials; we'll answer straight.
Every professional working under our name is required to carry the insurance coverage their state requires, including general liability and workers' compensation. We are part of the Garrison Partners family of brands, and every location operates under The Garrison Standard, which includes standing behind the work in writing. Ask for our insurance certificate before you sign; we're glad to provide it. Call (858) 264-3027 to request documentation for your project.
We work with a local San Diego team together with licensed subcontractors for specialized trades like electrical, plumbing, and concrete. Every trade that steps on your property is required to hold the license and insurance their state requires, and we manage that verification. The crew answers to one schedule and one standard: The Garrison Code. Show up inside the window we gave, do it by the book, and leave the site clean. Call (858) 264-3027 to meet the local team.
Reed Calloway leads the Fielding ADU San Diego branch. Reed runs the local operations and makes sure every job in San Diego, Encinitas, Santee, and the surrounding communities is built square, permitted, and finished on schedule. Fielding ADU Builders is the ADU company of the Garrison Partners family, and each location is independently owned and operated. When you call (858) 264-3027, a live coordinator connects you with Reed's team for your free estimate.
Emergency & Response FAQs
Call (858) 264-3027 during business hours and tell us what's happening. Our hours are Monday through Friday 7:00 AM to 7:00 PM, and Sunday 7:00 AM to 7:00 PM. We're closed Saturdays. If a permitted project is mid-build and something requires immediate attention, we'll address it on the next business day and keep you informed. For a true safety emergency, contact the appropriate utility or emergency service first.
We are open Monday through Friday from 7:00 AM to 7:00 PM, and Sunday from 7:00 AM to 7:00 PM. We're closed on Saturdays. Call (858) 264-3027 during those hours and a live coordinator will connect you with the local San Diego team. If you reach us after hours, leave a message and we'll return your call the next business day.
Your start date depends on the city's permit timeline, not just our schedule. Once plans are approved, we schedule the start date in writing and show up inside the window we gave. That is a Garrison Standard promise, and it's the standard we hold every job to. The fastest thing you can do today is call (858) 264-3027 to schedule your free on-site consultation and get your project in line.
Warranty & Guarantees FAQs
Every job we build is guaranteed in writing for a full year. If any part of the work fails during that year, we come back and make it right at no charge. That warranty is part of The Garrison Standard, and it's stamped on every Fielding ADU contract. We stand behind the work because we build it square and we build it to pass inspection the first time. Call (858) 264-3027 to get your written quote and see the warranty terms for yourself.
The Garrison Standard is the promise every Garrison Partners company works to. We arrive inside the window we gave you, put the price in writing before any work starts, do the job by the book, and leave the site clean. The work is guaranteed in writing for a full year, and if it fails in that time we come back and make it right at no charge. Fielding ADU San Diego is independently owned and operated, but we agreed to work to that standard. Call (858) 264-3027 to put it to work on your ADU.
The Garrison Code is the set of values every Fielding ADU location works by. Show up inside the window we gave. Price in writing before any work starts. Do it by the book, the first time. Leave the site clean and squared away. Stand behind the work for a full year. These aren't slogans; they're the operating rules our crew runs on every day. Call (858) 264-3027 and judge for yourself whether we live by the code.
Yes. If any part of the work fails within one year of completion, we come back and make it right at no charge. That's the warranty, in writing, in your contract. It covers the workmanship and the systems we installed, and we honor it without making you chase us. That is what The Garrison Standard requires. Call (858) 264-3027 to get a free estimate and see the written warranty before you decide.
Written by Reed Calloway, Owner at Fielding ADU San Diego, serving San Diego County since 2006.
Still Have Questions?
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(858) 264-3027